The present invention relates to a method for controlling a magnetic suspension vehicle.
Since the start of their development, magnetic suspension vehicles have been saddled with the problem that at low velocities or if the magnetic suspension vehicle is standing still, the overall system track/magnetic suspension vehicle has a tendency toward dynamic instability. Instability occurs in cases which involve modal track configurations with small masses and small relative damping, i.e., with the desired relatively elastic tracks. Even with relatively rigid tracks having large track masses it has been found that in some track configurations the overall system can be at the stability limit. Due to such dynamic instabilities, the system track/vehicle can start to vibrate, which can lead to strong vibration motions of the magnetic suspension vehicle and, in extreme cases, to damage to the track or parts of the magnetic suspension vehicle. For cost reasons, only tracks with small track mass, i.e., relatively elastic tracks, can be realized. These tracks are designed so that they take essentially only static traffic loads and have only small reserves for dynamic "supplementary" loads. It is therefore economically impossible to prevent the mentioned instabilities by erecting stiff tracks with large track masses. A solution to the problem can be found essentially only in the design of the magnetic suspension vehicle and in particular, by its "control intelligence".
The systems constructed so far provide no universal solution to the instability problem; mostly, compromises have been sought on an experimental basis which are sufficient for the limited requirements of experimental systems. However, these compromises apply only to the individual systems. They can therefore not apply to the desired application-oriented goal of making many types of track compatible and of meeting at the same time the necessary safety requirements.
For the method under discussion here, it is assumed that the magnetic suspension vehicle is supported and guided by self-sufficient, autonomic and decentralized magnets, so called magnetic wheels, where each magnetic wheel has its own control with processor, sensors, control elements, magnet-current-driver etc. It can further be assumed that the number of magnetic wheels acting on a track configuration is as a rule larger than three to four. Controls of this type for magnetic suspension vehicles are known, for instance, from DE-OS No. 31 17 971, assigned to the assignee of this application.